AngularJs Filter an array by another array

Question

I have three arrays in a controller:

1. $scope.allUsers containing all users by :id and :name. E.g. smth like this.

2. $scope.job.delegated_to containing information related to job delegation. Looks like this.

   $scope.job.delegated_to = [ {id: 5, user_id:33, user_name:"Warren", hour_count:4}, {id: 5, user_id:18, user_name:"Kelley", hour_count:2}, {id: 5, user_id:10, user_name:"Olson", hour_count:40}, {id: 5, user_id:42, user_name:"Elma", hour_count:2}, {id: 5, user_id:45, user_name:"Haley", hour_count:4}, {id: 5, user_id:11, user_name:"Kathie", hour_count:3} ]

3. $scope.freeUsers wich has to contain all the users, not delegated to the job.

I added a watch

$scope.$watch('job.delegated_to.length', function(){
  $scope.freeUsers = filterUsers( $scope.allUsers, $scope.job.delegated_to );
});

but have not been able to construct a working filter.

Answer 1

Your filterUsers function would be like:

var filterUsers = function(allUsers, jobs) {
    var freeUsers = allUsers.slice(0); //clone allUsers
    var jobUserIds = [];
    for(var ind in jobs) jobUserIds.push(jobs[ind].user_id);
    var len = freeUsers.length;
    while(len--){
      if(jobUserIds.indexOf(allUsers[len].id) != -1)  freeUsers.splice(len, 1);
    }    
    return freeUsers;
}

Checkout fiddle http://jsfiddle.net/cQXBv/

Answer 2

I would suggest using a library like Lo-Dash, which has many useful utility functions. You could then write your filter function as:

function filterUsers(allUsers, delegatedTo) {
    var delegatedIndex = _.indexBy(delegatedTo, 'user_id');
    return _.reject(allUsers, function(user) {return user.id in delegatedIndex});
}